Conventionally, a vehicle periphery monitoring device has been proposed, which detects a three-dimensional object in the periphery of a vehicle and which also detects whether or not the three-dimensional object remains stationary or is moving. This vehicle periphery monitoring device converts two images captured at different times into bird's-eye views, performs a position adjustment of the two bird's-eye views, obtains differences between the two images after the position adjustment, and detects unmatched portions as a three-dimensional object. See, for example, Patent Application Publication No. 2008 219063 A.